Eagle Electric Bikes charges its customers a per-minute fee for bike rentals. The first time Ross rented from them, he got a $10 new-customer discount and used the bike for 64 minutes. The second time, he used the bike for 39 minutes. He noticed that he was charged the same amount each time.

Question

What is the per-minute fee to rent an electric bike?

Answer 1

Let the per-minute fee be denoted as \( x \).

For Ross's first rental, he received a $10 discount and used the bike for 64 minutes. The total charge for that rental can be expressed as:

\[ \text{Total charge for first rental} = 64x - 10 \]

For the second rental, Ross used the bike for 39 minutes, and the total charge for this rental is:

\[ \text{Total charge for second rental} = 39x \]

According to the problem, both total charges are the same:

\[ 64x - 10 = 39x \]

To solve for \( x \), we can start by isolating \( x \). Subtract \( 39x \) from both sides:

\[ 64x - 39x - 10 = 0 \] \[ 25x - 10 = 0 \]

Next, we add 10 to both sides:

\[ 25x = 10 \]

Now, divide both sides by 25:

\[ x = \frac{10}{25} = \frac{2}{5} = 0.4 \]

Thus, the per-minute fee to rent an electric bike is

\[ \boxed{0.40} \text{ dollars per minute.} \]

We can verify this by checking the total charges for both rentals:

1. First rental charge:

   • \( 64 \times 0.4 - 10 = 25.6 - 10 = 15.6 \)

2. Second rental charge:

   • \( 39 \times 0.4 = 15.6 \)

Both charges are indeed equal, confirming that the calculation is correct. Thus, the per-minute fee is \( \boxed{0.40} \).